The first season... I cant really describe what made it great. Pikachu that didnt destroy everyone, The plot was interesting, and had several moments that go alongside the game (what happened after you left the SS ann), who could forget the pokerap(e) *shotted* , or maybe it was the idea that the storyline moves in a way that ACTUALLY IS TO BE CONTINUED!
at the end of the episode, it says "to be continued". In the old show, I cant watch randomly placed shows, due to the fact that many to most of them happen because of the last one. In the RSE generation, I can randomly pick a spot. go from a beach in oldale, to perhaps a stranded wailord halfway across hoenn! there is never an indicator on where they are unless you watch the series
CLOSELYthey have to arrive at vermilion city in order to board the SS ANN. with landmarks from the game everywhere, it truely is "to be continued". sometimes, we dont know where on earth they are, like the charmander episode, but a majority of the time, there is no route 51.
Overall, when pokemon entered the RSE era, they jumped the shark for the anime. the lack of interesting characters and landmarks, the route 51 episodes, and *shudder* the addition of pokemon contests has watered the series down.